Goodwill and Other Intangible Assets - Mortgage Servicing Rights - Activity in Valuation Allowance (Details 4) (Mortgage servicing rights [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Mortgage servicing rights [Member]
Activity in valuation allowance for mortgage servicing rights
Valuation allowance, beginning of period	$ (793)	$ (201)	$ (250)
Additions		(592)
Reductions	296		49
Direct write-downs
Valuation allowance, end of period	$ (497)	$ (793)	$ (201)

Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e24092-122690

Name:	us-gaap_ValuationAllowancesAndReservesDeductions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration